MATLAB: App Designer : Text field making visible and invisible when select and re-select same option from drop down menu

app designerdrop down

I am trying to make a text field visble when I select an option form the drop down and when I re-select that option, I want to make that text field hide. Please suggest me how to do this using drop dwon.

Best Answer

You can create a property called

Last_Selection = '';

In the DropDownMenu callback

function DropDownValueChanged(app,event)
    if isempty(app.Last_Selection)
        app.Last_Selection = app.DropDownMenu.Value % Initialises Last_Selection on first callback
    else
        if isequal(app.Last_Selection, app.DropDownMenu.Value)
            % Hide something
            % I am not sure how it goes with hiding/removing dropdown values
            % First you have to assign to some other dropdown value and then remove it
            % if you don't want errors
            % ind = find (app.DropDownMenu.Value == app.DropDownMenu.Items); % get index of data to be removed
            % app.DropDownMenu.Value = change_to_other_value
            % app.DropDownMenu.Items{1,ind} = ''; % Test if it actually works
        else
            app.Last_Selection = app.DropDownMenu.Value
        end
        
    end
end

The question is, does the callback gets executed if the DropDownMenu.Value stays the same?

It might be more intuitive to the user what to do to remove the dropdown value, by adding the button instead.

Related Solutions

MATLAB: Appdesigner button group problem

Enabled property is not valid for Button Group but valid for Button. So, app.Button.Enable = 'off' will work.

%% Create UIFigure
app.UIFigure = uifigure;
app.UIFigure.Position = [100 100 640 480];
app.UIFigure.Name = 'UI Figure';
% Create ButtonGroup
app.ButtonGroup = uibuttongroup(app.UIFigure);
app.ButtonGroup.Title = 'Button Group';
app.ButtonGroup.Position = [282 115 123 106];
% Create Button
app.Button = uiradiobutton(app.ButtonGroup);
app.Button.Enable = 'off';
app.Button.Text = 'Button';
app.Button.Position = [11 60 58 22];
app.Button.Value = true;
% Create Button2
app.Button2 = uiradiobutton(app.ButtonGroup);
app.Button2.Enable = 'off';
app.Button2.Text = 'Button2';
app.Button2.Position = [11 38 65 22];
% Create Button3
app.Button3 = uiradiobutton(app.ButtonGroup);
app.Button3.Text = 'Button3';
app.Button3.Position = [11 16 65 22];
%% Disable all buttons 
app.Button.Enable = 'off';
app.Button2.Enable = 'off';
app.Button3.Enable = 'off';

Also, Button Group has Visible property, so you can hide button group by the following.

app.ButtonGroup.Visible = 'off';

MATLAB: Using Matlab App Designer with 2 Dependent Pop Up Menus

You can do this by using a callback on changinge the value in your first drop down. All the magic is done in

function DropDown1ValueChanged(app, event)

Here you go:

classdef app1 < matlab.apps.AppBase
    % Properties that correspond to app components
    properties (Access = public)
        UIFigure          matlab.ui.Figure
        DropDown2_2Label  matlab.ui.control.Label
        DropDown2_2       matlab.ui.control.DropDown
        DropDown1Label    matlab.ui.control.Label
        DropDown1         matlab.ui.control.DropDown
    end
    methods (Access = private)
        % Value changed function: DropDown1
        function DropDown1ValueChanged(app, event)
            value = app.DropDown1.Value;
            switch value
                case "California"
                    app.DropDown2_2.Items = {'San Diego', 'Sacaramento', 'Irvine'};
                case "Texas"
                    app.DropDown2_2.Items = {'Austin', 'Dallas', 'Houston'};
            end
                    
        end
    end
    % App initialization and construction
    methods (Access = private)
        % Create UIFigure and components
        function createComponents(app)
            % Create UIFigure
            app.UIFigure = uifigure;
            app.UIFigure.Position = [100 100 640 480];
            app.UIFigure.Name = 'UI Figure';
            % Create DropDown2_2Label
            app.DropDown2_2Label = uilabel(app.UIFigure);
            app.DropDown2_2Label.HorizontalAlignment = 'right';
            app.DropDown2_2Label.Position = [370 287 69 22];
            app.DropDown2_2Label.Text = 'DropDown2';
            % Create DropDown2_2
            app.DropDown2_2 = uidropdown(app.UIFigure);
            app.DropDown2_2.Items = {'San Diego', 'Sacaramento', 'Irvine'};
            app.DropDown2_2.Position = [454 287 100 22];
            app.DropDown2_2.Value = 'San Diego';
            % Create DropDown1Label
            app.DropDown1Label = uilabel(app.UIFigure);
            app.DropDown1Label.HorizontalAlignment = 'right';
            app.DropDown1Label.Position = [97 287 69 22];
            app.DropDown1Label.Text = 'DropDown1';
            % Create DropDown1
            app.DropDown1 = uidropdown(app.UIFigure);
            app.DropDown1.Items = {'California', 'Texas'};
            app.DropDown1.ValueChangedFcn = createCallbackFcn(app, @DropDown1ValueChanged, true);
            app.DropDown1.Position = [181 287 100 22];
            app.DropDown1.Value = 'California';
        end
    end
    methods (Access = public)
        % Construct app
        function app = app1
            % Create and configure components
            createComponents(app)
            % Register the app with App Designer
            registerApp(app, app.UIFigure)
            if nargout == 0
                clear app
            end
        end
        % Code that executes before app deletion
        function delete(app)
            % Delete UIFigure when app is deleted
            delete(app.UIFigure)
        end
    end
end

Greetins Stefan

Best Answer

Related Solutions

MATLAB: Appdesigner button group problem

MATLAB: Using Matlab App Designer with 2 Dependent Pop Up Menus

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